Reflection and interference of electromagnetic waves in inhomogeneous media

Solutions were obtained of the wave equation for a plane horizontally polarized electro-magnetic wave incident on a semi infinite two dimensional inhomogeneous medium. Two problems were considered: An inhomogeneous half space, and an inhomogeneous layer of arbitrary thickness. Solutions of the wave equation were obtained in terms of Hankel functions with complex arguments. Numerical calculations were made of the reflection coefficient R at the interface of the homogeneous medium. The startling results show that the reflection coefficient for a complex dielectric constant with gradient, can be less than that of the same medium with zero gradient

Research Methods in Studying Reading and Literacy Development in Deaf Children Who Sign

This chapter discusses research concerning deaf individual’s reading and spelling development, with a focus on collecting literacy data from deaf children and adolescents. I will begin by presenting an overview of what we know about reading development in deaf individuals covering topics such as: What are the reading achievements of deaf children? How do deaf children learn to read? Do they learn to read in a similar way to hearing children? This will be followed by a more detailed discussion of the different types of methodologies that have been used to conduct literacy research with deaf children, highlighting important findings. Lastly I will describe some of the issues involved with researching literacy development in deaf children who sign and potential ways of dealing with these issues

Photomechanical Investigation of Structural Behavior of Gyroscope Components. Task IV - Analysis of Initial Redesign of AB5-K8 GYROSCOPE

Photomechanics of structure and materials in redesigned AB5-K8 gyroscope component

Concurrent and longitudinal predictors of reading for deaf and hearing children in primary school

Forty-one children with severe-profound prelingual hearing loss were assessed on single word reading, reading comprehension, English vocabulary, phonological awareness and speechreading at three time points, one year apart (T1, T2, T3). Their progress was compared with that of a group of hearing children of similar non-verbal IQ, initially reading at the same level. Single word reading improved at each assessment point for the deaf children but there was no growth in reading comprehension from T2 to T3. There were no differences between children with cochlear implants and those with hearing aids on either reading measure but orally-educated children had higher scores than children who signed in the classroom. English vocabulary and speechreading were the most consistent longitudinal predictors of reading for the deaf children. Phonological awareness was the most consistent longitudinal predictor for the hearing group and also a concurrent predictor of reading at T3 for both groups. There were many more significant correlations among the various measures for the deaf children than the hearing at both T1 and T3, suggesting that skills underpinning reading, including phonological awareness and vocabulary, are more closely related for deaf children. Implications of these findings for of deaf children’s literacy are explored

Literacy and phonological skills in oral deaf children and hearing children with a history of dyslexia

Oral deaf children and hearing children with dyslexia both experience literacy challenges, although their reasons differ. This paper explores the problems underlying poor literacy in each group and draws implications for reading interventions. Data were collected using standardised literacy and phonological measures from 69 severe-profoundly prelingually-deaf children aged 10-11 years, all communicating with spoken language, and compared with equivalent data from 20 hearing children with a history of dyslexia matched on reading ability. Children were given a large battery of tasks assessing word and nonword reading, spelling, vocabulary and reading-related skills including lettersound knowledge, phonological awareness, rapid automated naming and verbal short-term memory. Striking similarities were observed for word reading, nonword reading and spelling across groups, and associations between the measures and reading-related skills were similar. However, differences between the two groups emerged in the strength of association between literacy and vocabulary. Regression analyses confirmed vocabulary as a key predictor of literacy in the oral deaf group. These results suggest that not only children with a history of dyslexia but also oral deaf children who struggle with reading should receive specialist literacy support. Reading interventions for oral deaf children should target phonological and language skills within a fully integrated approach

Reading and Dyslexia in Deaf Children

Literacy difficulties are more widespread among deaf children than hearing children but reasons for their problems differ. Hearing children are likely to be described as dyslexic and once diagnosed, may benefit from specialist support. However, for deaf children, their hearing difficulties are seen as primary. In this Briefing Paper, we report findings from a two-phase research study on deaf children’s reading, funded by the Nuffield Foundation. Phase 1 focused on a large sample of 82 same-age deaf children aged 10-11 years who communicated using spoken language (oral deaf children) and Phase 2, on a sample of 59 same-age deaf children who used sign language to communicate (signing deaf children). Our analysis identified that literacy scores in both deaf groups were lower than expected for their age, and lower in the signing group compared to the oral group. An exception was the small group of signing children with two deaf parents, who achieved reading levels comparable to oral deaf children. Overall, 48% of the oral group and 82% of the signing children were reading below age level. Scores for spelling were better than reading but in both groups, many children had below average scores. In both groups, literacy outcomes were associated with phonological skills and language. Profiles of poor readers in each group were similar, and displayed low scores on English expressive vocabulary and phonological measures. Using our hearing dyslexic participants as a reference group, we were able to identify dyslexia-sensitive measures that were effective in differentiating poor readers in the oral deaf sample since children in the oral deaf group were able to access the full range of measures developed for hearing children. Identification of a dyslexic profile among the signing participants was more complex as different phonological measures were used that did not rely on speech perception or production, and also because of their very low scores on many of the measures: the percentage of poor readers with scores falling below -2 SDs was nearly four times higher in the signing group compared with the oral deaf group, accounting for nearly a quarter of the signing sample. Our findings highlight the scale of reading difficulties in deaf children. Regardless of communication approach, all deaf poor readers are in urgent need of specialist intervention to address the deficits underlying poor literacy. Interventions known to be effective with hearing children with reading difficulties should also be used with deaf poor readers. In addition, deaf children require support to develop their language skills. Our findings also suggest that spelling, a relative strength in deaf children, may offer a useful route to improving literacy in this group

Contribution of family risk, emergent literacy and environmental protective factors in children’s reading difficulties at the end of second-grade

It is well established that emergent literacy is a strong predictor of later reading difficulties, and that the home literacy environment plays an important role in the development of children’s preschool emergent literacy and oral language. Furthermore, reading difficulties runs in families and children with a family risk of reading difficulties tend to show delays in emergent literacy and might experience a less advantageous home literacy environment. This study examined whether family risk predicts children’s second-grade reading difficulties in a multifactorial model including both emergent literacy and environmental protective factors such as home literacy environment and parental level of education. Children were assessed for emergent literacy at the beginning of first grade, and were identified as having reading difficulties at the end of second grade if they performed below the national threshold in at least three of the subtests in reading and spelling. The multifactorial model suggested that children with family risk showed reading difficulties that could not be explained in terms of individual differences in emergent literacy, gender, interest in literacy, years in kindergarten, home literacy environment or parental education level. These findings highlight the advantages of using multifactorial models of reading difficulties that encompass different domains of genetic, cognitive-based and environmental factors. In sum, not only did we find family risk is associated with children’s literacy outcomes after 2 years of formal reading instruction, but we also identified possible modifiable factors that may benefit from interventions and lessen the likelihood of developing reading difficulties

Ohio Livestock Waste Management Guide

PDF pages: 3